82 



Pile shorter and denser throughout, the posterior tibiae with white pile, their 

 tarsi almost pure reddish on the first two joints, but the first is darker above. 

 The abdomen lacks the sub-opaque areas and the insect is more slender. 



Holotype. — 2, Bathurst, New Brunswick. June 15, 1923 (J. N. Knull); No. 

 776, in the Canadian National Collection, Ottawa. 



Allotype. — ?, Jaffrey, New Hampshire, June 17 (C. W. Johnson). 



Paratypes. — i$, Chester, Massachusetts, August 6 (C. W. Johnson); $, 

 Alstead, New Hampshire, August 8, 1914 (A. P. Morse). 



The allotype and four paratypes are in the Museum of the Boston Society of 

 Natural History. 



Fig. 1. — Pipiza nigrotibiata, sp. nov. Head in profile. 

 Fig. 2. — Posterior femur and tibia. 



Pipiza nigrotibiata is a very distinct species and is readily dis- 

 tinguished from its allies. The only confusion which may arise con- 

 cerning the identity of the 9 may be expected in the case of P. 

 severnensis Curran and tricolor Curran. This latter may be elim- 

 inated on account of its much smaller size and absence of femoral 

 angles, while severnensis, (as I remember the $ ) has the femora no 

 larger than in femoralis Lw. and both these females may have a 

 reddish abdominal fascia, as neither is known. None of the other 

 eastern species has the hind tibiae black pilose and there should not, 

 therefore, be any confusion. 



